Coaxial cable connector



Feb. 6, 1968 M. H. BURDETT ETAL COAXIAL CABLE CONNECTOR Filed Dec. 8, 1965 INVENTORS B. BUCHLER .H. BURDETT D. M BY United States Patent COAXIAL CABLE CONNECTOR Malcolm H. Burdett, Indianapolis, Ind., and Daniel B. Buchler, Burnsville, Minn, assignors, by direct and mesne assignments, to The Anaconda Wire and Cable Company, New York, N.Y., a corporation of Delaware Filed Dec. 8, 1965, Ser. No. 512,479

4 Claims. (Cl. 17475) Our invention relates to connecting means for cables having coaxial conductors and particularly to connecting means for cables having dielectric jackets bonded to the outer of said conductors.

Coaxial cables of the type for which suitable connectors have long been known have comprised an outer conductor consisting of a copper braid and a polyethylene dielectric jacket over the braid. When connections were made to such cables it was a simple matter to strip the jacket from a terminal length of the cable and to clamp or solder a connecting element to the exposed braid.

Connectors of known types have, however, proven to be entirely unsuitable for a type of coaxial cable which has recently found widespread utility. This cable has an outer conductor which comprises an aluminum or copper foil that is strongly bonded to itself at an overlap and is also bonded to the overlying dielectric jacket. Because of the bond the jacket cannot be readily removed to expose the conductor, nor can the conductor be greatly expanded in the manner of a braid.

We have now invented a connector that is capable of making excellent connections to the new type of coaxial cables both electrically and mechanically.

Our connector comprises a cylindrical electrically conducting shell with a shoulder, that may be circular and normal to the axis of the shell, extending radially inwardly. Our connector also comprises a bushing having a thin-walled tubular length insertable between the conductor and the wall of cable insulation, and a flange that matches the aforementioned shoulder. When the thinwalled length of the bushing is inserted it makes a good wiping electrical contact with the outer conductor and the electrical path is continued unbroken by the contact between the flange of the bushing and the shoulder extending from the shell. We have provided a split ring that is tapered inwardly and fits over both the tubular length of the bushing and the jacket and abuts the flange, and a clamping ring tapered to match the taper of the split ring. In our connector there are means for urging the clamping ring against the split ring so that the flange is urged against the shoulder, making good electrical contact therewith, and the jacket and outer conductor are compressed between the split ring and the tubular length of the bushing. Preferably the shell of our connector is threaded and the urging means comprises a nut that engages the threads of the shell.

A more thorough understanding of our invention can be gained from a study of the appended drawing.

The figure shows a male connector, indicated generally by the numeral 10, for a coaxial cable indicated generally by the numeral 11 and comprising an inner conductor 12, a wall 13 of dielectric insulation such as extruded polyolefin. Although we do not wish it to be limiting, our connector is particularly adapted to cables where the dielectric wall 13 is comprised of expanded polyethylene. Over the insulation 13 the cable 11 has an outer conductor 14 of copper or aluminum. The conductor 14 of the illustrated cable is comprised of a longitudinal overlapped tape. The tape is firmly bonded to itself at the overlap and this, of course, limits its circumferential extensibility. Our connector is particularly useful for connecting cables of the type shown but it can also be used 3,368,025 Patented Feb. 6, 1968 with other known coaxial cables such as those with braided outer conductors which have substantial extensibility.

The conductor 14 is covered with a dielectric jacket 16 that is firmly bonded to it in the manner disclosed in an application Ser. No. 422,275, assigned to the assignee of the present invention.

The connector 10 comprises a cylindrical shell 17 with an inwardly extending annular shoulder 18 normal to the shell axis and an internal threaded portion 19. A bushing 21 has a thin tubular length 22 that is inserted between the wall 13 and conductor 14. The length 22 has a sharpened edge 23 and because of its thinness can be readily inserted under the conductor 14 without tearing the latter in spite of its limited stretchability. The bushing 21 also comprises a right-angle flange 24 that fits in good electrical contact against the shoulder 18. A split ring 26 fits over the jacket 16 and the inserted length 22, and is abutted against the flange 24. The ring 26 is tapered inwardly by a bevel 27 so that it can be compressed by means of a compression ring 28 so as to squeeze the jacket and outer conductor onto the bushing 21. For this purpose the compression ring 28 has a matching taper or bevel 29. The ring 28 fits a notched sealing gasket 31 which is separated from a nut 32 by a washer 33. The nut 32 threads into the threaded portion 19 of the shell 17 and when it is turned it expands the gasket 31 to seal the connector, compresses the ring 26 to make good electrical contact between the tape 14 and the bushing 21 and also presses the ring 26 against the flange 24 so that the latter makes permanent electrical contact of low resistance with the shoulder 18.

We have described one embodiment of the novel elements of our invention, the remaining features of our connector being conventional wherein the conductor 12 is soldered into a male contact 34 that is maintained in electrical separation from the shell 17 by dielectric spacers 36, 37. A threaded swivel cap 38 connected to the shell 17 by means of an imbedded locking ring 39 serves to fasten the connector to a female member of known type. While we have shown our connector associated with a male contact, it will be understood that it may also be connected to female contacts, of which many types are known, within the scope of our invention.

To use the connector of our invention for a cable such as the cable 11, the outer conductor 14 and jacket 16 are cut square and removed to expose a 2-inch length of the dielectric 13. This is easy to do since although the outer conductor is bonded to the jacket it is not bonded to the dielectric 13. The nut 32, washer 33, gasket 31, and rings 28, 26 are then slid, in that order, over the end of the cable. The dielectric is rotated by hand enough to loosen it from the outer conductor, and the bushing 21 is slid over the dielectric and under the outer conductor until the cut end of the jacket is flush against the flange 24. The dielectric 13 is then trimmed off flush with the end of the bushing 21 leaving a length of the conductor 12 projecting. The contact 34 and spacer 37 are then placed over the conductor 12 and crimped or soldered in a known manner. The washer 33 is pushed forward sliding the elements ahead until the ring 26 abuts the flange 2'4. Thereafter the spacer 36 is put on and the assembly is inserted into the shell 17. The nut 32 is then threaded into the shell to compress the gasket 31 and the ring 26.

The foregoing description of our invention is exemplary rather than definitive and other embodiments will be included within the scope of our invention defined by the following claims.

We claim:

1. A connector for a coaxial cable of the type having 3 4 a dielectric jacket bonded to the outer conductor and a (F) means for urging said clamping ring against said wall of insulation under said conductor comprising: split ring whereby said flange is urged against said (A) a cylindrical, electrically conducting shell, shoulder, making good electrical contact therewith, (B) a radially inwardly extending shoulder formed in and said jacket and outer conductor are compressed said shell, 5 between said split ring and said tubular length of (C) a bushing fitting within said shell, said bushing.

(a) said bushing having a thin-walled tubular 2. The connector of claim 1 wherein said urging means length insertable between said conductor and comprises a nut threaded to said shell. said wall, and 3. The connector of claim 1 wherein said shoulder is (b) a flange matching said shoulder, 10 circular. (D) a split ring 4. The connector of claim 3 wherein said shoulder is (a) abutting said flange, and normal to the axis of said shell. (b) fitting over said tubular length and capable of enclosing said jacket, No references cited.

(c) said ring being tapered inwardly, 1 (E) a clamping ring tapered to match the taper of said split ring, and

5 DARRELL L. CLAY, Primary Examiner. 

1. A CONNECTOR FOR A COAXIAL CABLE OF THE TYPE HAVING A DIELECTRIC JACKET BONDED TO THE OUTER CONDUCTOR AND A WALL OF INSULATION UNDER SAID CONDUCTOR COMPRISING: (A) A CYLINDRICAL, ELECTRICALLY CONDUCTING SHELL, (B) A RADIALLY INWARDLY EXTENDING SHOULDER FORMED IN SAID SHELL, (C) A BUSHING FITTING WITHIN SAID SHELL, (A) SAID BUSHING HAVING A THIN-WALLED TUBULAR LENGTH INSERTABLE BETWEEN SAID CONDUCTOR AND SAID WALL, AND (B) A FLANGE MATCHING SAID SHOULDER, (D) A SPLIT RING (A) ABUTTING SAID FLANGE, AND (B) FITTING OVER SAID TUBULAR LENGTH AND CAPABLE OF ENCLOSING SAID JACKET, (C) SAID RING BEING TAPERED INWARDLY, (E) A CLAMPING RING TAPERED TO MATCH THE TAPER OF SAID SPLIT RING, AND (F) MEANS FOR URGING SAID CLAMPING RING AGAINST SAID SPLIT RING WHEREBY SAID FLANGE IS URGED AGAINST SAID SHOULDER, MAKING GOOD ELECTRICAL CONTACT THEREWITH, AND SAID JACKET AND OUTER CONDUCTOR ARE COMPRESSED BETWEEN SAID SPLIT RING AND SAID TUBULAR LENGTH OF SAID BUSHING. 